Method and apparatus for making cartons from blanks



Sept. 19,1967 M. B. DUNN 3,342,114

METHOD AND APPARATUS FOR MAKING CARTONS FROM BLANKS Original Filed Nov. 27, 1962 3 Shees-Sheet 1 2M ZZ 250 234 238) 244 28 4 260- 254 270 r230 L 8 z4- 7 Q I (2/8) z z z zz 204 7226 Z74 ZZZ Z/Z Z06 INVENTOR MA 08/663 Dom/Y Sept. 19, 1967 M. a. DUNN 3,342,114

METHOD AND APPARATUS FOR MAKING CARTONS FROM BLANKS Original Filed Nov. 27, 1962 s Sheets-Sheet 2 M. B. DUNN Sept. 19, 1967 METHOD AND APPARATUS FOR MAKING CARTONS FROM BLANKS 5 Sheets-Sheet 5 Original Filed Nov. 27 1962 19km x232 INVENTOR ATTORNEYS United States Patent 3,342,114 METHOD AND APPARATUS FOR MAKING CARTUNS FROM BLANKS Maurice B. Dunn, Charlotte, N.C., assignor to Memco Machinery Corporation, Charlotte, N.C., a corporation of North Carolina Original application Nov. 27, 1962, Ser. No. 240,298, now Patent No. 3,226,006, dated Dec. 28, 1965. Divided and this application Sept. 10, 1964, Ser. No. 403,675 8 Claims. (Cl. 93-51) This invention relates to a foldable blank for forming cartons, such as containers or covers. It also relates to the resultant carton, and to a method and apparatus for erecting or setting up the carton.

This application is a division of my copending application Ser. No. 240,298, filed Nov. 27, 1962, now US. Patent No. 3,226,006.

Paperboard or like type cartons are well-known, and are frequently employed in many different industries, for example to enclose bakery goods. The sort of carton which this invention contemplates may be so utilized, but limitation thereto is not intended since its use is obviously of greater potential. One of the disadvantages of prior art cartons, such as the box and box blank in FIGURES 1 and 2 of the Meller Patent No. 2,634,899, granted Apr. 14, 1953, is that it cannot be erected or set up automatically by machinery, but instead requires manual operation to effect the complete locking of adjacent side panels. On the other hand, cartons such as that referred to in the Dunn Patent No. 3,029,712, granted Apr. 17, 1962, which can be automatically erected by machines have the disadvantage of their adjacent side panels being too easily unlocked.

It is the object of this invention to overcome both of these prior art disadvantages so as to provide a carton blank which can, though it need not be, automatically set up by machinery into an erected operative position in which its adjacent side panels are positively locked and not capable of being inadvertently unlocked.

Another object of this invention is the provision of a method and apparatus for setting up such a positive locking carton.

Other objects and advantages of this invention will become apparent to those of ordinary skill in the art upon reading the appended claims and the following detailed description of the invention in conjunction with the attached drawings, in which:

FIGURE 1 is a plan view of a fiat carton blank embodying this invention, the inside surface of the blank facing the observer;

FIGURE 2 is a perspective view of a carton set up from the blank shown in FIGURE 1, left end interlocks being shown in half completed condition;

FIGURE 3 is an elevational front view of the lower left corner of FIGURE 2 as indicated by the line 3-3;

FIGURE 4 is the same view as FIGURE 3 but show ing the flexing operation necessary to get the tab tip tucked in; 7

FIGURE 5 shows an inside view of the upper left corner of FIGURE 2 in cross-section and elevation during the tip tucking in operation;

FIGURE 6 is the same view as FIGURE 3 except with the tab tip tucked into locked position;

FIGURE 7 is a fragmentary, plan, sectional view illustrating the carton erecting machine embodying the principles of the present invention; and

FIGURE 8 is an elevational view of the assembly shown in FIGURE 7, from the lower side thereof.

FIGURES 7 and 8 in this application are respectively similar to FIGURES l and 2 of the above-mentioned Dunn Patent No. 3,029,712, with modifications necessary to effect erecting of the carton blank of FIGURE 1 herein into the carton of FIGURE 2. The modifications made to the machine in that Dunn patent are discussed below and reference may be made to that patent for any other details not set forth herein.

In the carton blank shown in FIGURE 1, the central area defined within hinge or fold lines 200, 202, 204 and 206 is the main or inside panel 208 of the carton, forming for example the bottom panel thereof. It must be appreciated however, that the carton while its main use may generally be as a container or box, may likewise be used as a cover or lid in which case the main panel 208 would become the top of the carton.

Hinged to the respective edges of main panel 208 are side panels 210, 212, 214 and 216. For convenience, the panels 212 and 216 are herein sometimes referred to as end panels and panels 210 and 214 as side panels because the former are illustrated shorter than the latter, but it is to be appreciated that the reverse may be true or that all of the outside panels may be of the same length.

As shown in FIGURE 1 each of the end panels 212 and 216 have attached to each of their end edges via a hinge or fold line, a respective flap. For example, end panel 212 has hinged thereto along the fold line 218 a flap 220, and at its other end along the fold line 222 there is hinged a flap 224. Likewise, end panel 216 has hinged to it at respective fold lines 226 and 228 the flaps 230 and 232.

The fold lines above mentioned may be of the cut and scored type as is conventional for allowing ease of folding along a given predetermined line. Additionally, fold lines 218 and 226 are either aligned with, or preferably parallel and slightly offset outwardly with respect to, the fold line 204 to compensate for the thickness of the sheet material in the succeeding folding operations, as is customary in the art. A similar sort of situation may exist as to fold lines 222 and 228 relative to the side fold line 200. Generally, an offset or bending allowance, for example %2", is desirable.

It will be noted from FIGURE 1 that each of the side panels 210 and 214 includes two cuts or internal silts respectively designated 234, 236, 238 and 240. Each of these slits has a triple directional characteristic, that is, each has a vertical element 242, a sloping element 244, and a horizontal element 246 the purpose of which will be more apparent from the latter description of the carton setting up procedure.

Each end edge of each of the side panels 210 and 214 is uniquely formed with first and second portions 248 and 250successively proceeding from the intersection 252 at different angles.

Since each of the corners of the carton blank in FIG- URE 1 is the same as each other corner, reference is now made only to the upper left corner of FIGURE 1.

In the specific embodiment illustrated in FIGURE 1, the first portion 248 of the end edge of side panel 214 proceeds outwardly from intersection 252 substantially in line with the hinge line 202, i.e., at an angle of substantially relative to hinge line 204. It will be later apparent that this end edge portion 248 may extend outwardly from the intersection 252 also at either an acute or oblique angle relative to fold line 204, the main feature of the carton blank being that the second end edge portion 250 extends at an inwardly rotated acute angle, for example 12, relative to end portion 248. This angle may be considerably increased, or decreased to some extent, and the intersection 254 of these end portions may be moved up or down somewhat within the scope of this invention, though intersection 254 preferably falls on an imaginary line that is parallel to fold line 204 and spaced therefrom approximately midway to the outer edge of side panel 214.

Flap 220 includes a main body portion 256 and a tab 258 having a tip 260. The upper outer edge 262 of the tab is preferably horizontal while its sloping edge 264 makes an exemplary angle of 45 with the horizontal and vertical. The inner open edge 266 of flap 220 extends from intersection 252 preferably at an angle to the vertical, for example 12, but no limitation to such an angle is intended since the angle may be reduced to as well as increased up to a value of about 30 for example.

Again as exemplary, the angle of portion 244 of slit 234 may be 42 relative to the horizontal, this being preferably slightly less than the angle of tab edge 264 for better locking purposes, and the length of slit portion 246 may be such as to extend to the are centered on intersection 252 and which would intersect an extension of tab edges 262 and 264. Vertical slit element 242 extends closer to fold line 204 as the angle between flap edge 266 and vertical approaches 0.

The carton blank of FIGURE 1 may be erected into a box or container like that shown in FIGURE 2 by simple manipulation of the different foldable parts of the blank, along with a pivotal flexing or bending operation to cause the tab tip to completely enter the slit in the adjacent side panel, all as now fully described in detail.

Generally speaking, the making of the carton in FIG- URE 2 will normally start with the FIGURE 1 blank being in a substantially flat position as illustrated. It is then necessary to start folding the different side panels upwardly about their respective fold lines 200, 20-2, 204 and 206, and to begin folding the end flaps 220, 224, 230 and 232 inwardly. In the specific example illustrated, adjacent side panels eventually come into a substantially right angle relationship with each other and the main or bottom panel 208, but it is to be realized that such a right angle relationship is not essential to this invention since the carton may have more or less than four corners, and since either the side panels 210', 214 or the end panels 212, 216 or both may make either an acute or oblique angle with the main panel 208 when in their erected and locked position, as desired.

In folding up the outside panels, side panels 210 and 214 are folded up before end panels 212 and 216, so that the flaps 220', 224, 230 and 232, which may be folded toward a right angle relationship with their respective end panels while that end panel is being folded up, may have their interior surface in substantially abutting relationship with the exterior surface of the respective end portion or part of the adjacent side panel 210, 214.

In the meantime, slits 234, 236, 238 and 240 are opened by relatively moving the portions of the side panels on either side of the slits in opposite directions, for example by moving the outer portion 268 outwardly without, but preferably with, concurrent movement of the interior portion 270 inwardly. Then, as the end panels 212 and 216', with their respective pairs of flaps folded at substantially right angles with the end panels, come into a right angular relationship with main panel 208, the lower portion 272 of each end of each end panel 212 and 216 abuts the end edge 248 of the adjacent end portion of the respective side panel 210, 214. The end panels 212 and 216 can then be no further rotated about their respective hinge lines 202 and 206, since abutments 248 act as stops and prevent such further rotation of the end panels, and consequently of their pairs of flaps.

The right end corners of the carton in FIGURE 2 show the end and respective side panels completely locked, but for the moment attention is turned to the left end corners of FIGURE 2 since they both illustrate the situation as it exists at the present point of the setting up procedure. It will be noted that tabs 258 of flaps 220 and 224 are disposed out of overlapping relation with the respective cuts or slits 234 and 236, i.e., that tips 260 of those fiaps are still on the exterior side of side panels 210 and 214 though large parts of tabs 258 are on the inside of those side panels.

For greater clarity, reference is made to FIGURE 3 to indicate the just explained condition as to the lower left corner of FIGURE 2. In particular, in FIGURE 3 it will be seen that the tab tip 260 extends above the horizontal portion 246 of slit 236, and consequently there is as yet no locking by the flap 224 since its tab 258 is not completely through the slit. At this stage in the procedure in the prior art, such as in the Meller patent above referred to, the tab tips are pulled through the slit manually by flexing the tabs sidewise appropriately. With the present invention, there is no need to bend or flex the tab at all, and therefore automatic machinery can cause the flap and side panel to be interlocked, in the manner now explained.

The intersection 254 of the lower stop portion 248 and the upper relieved portion 250 of the end edge at each end of each side panel, forms a respective fulcrum about which the adjacent end portion of each of the end panels 212, 216 may be inwardly flexed, bent, deflected, pivoted, or rotated, as you will, by pressure on the exterior surface of the upper part 274 against the natural bias of the end panel 212, 216, as shown in FIGURES 4 and 5. As apparent, this rotates the respective flap and its tab tip 260 inwardly toward the hinge line 200 or 204 between the adjacent side and main panels. Generally, the pressure or force causing such rotation is sufficient to make the upper part 274 abut the relieved end edge portion 250 of the side panel, but it is to be understood that such abutment per se is not essential though generally preferred, according to the angle of relief of portion 250 and the degree of locking security desired. The main point here is that the external pressure on part 274 causes tab tip 260* to rotate inwardly and downwardly sufficiently to come fully below the horizontal element 246 of the slit so that the tab 258 fully enters the slit. It then has its outside surface substantially abutting the inside surface of the inner end part 270 of the adjacent side panel end portion while the remainder of the flap has its inside surface substantially abutting the outside surface of the outer part 268 of the same side panel end portion.

For clarity, FIGURES 4 and 5 show the lower part 272 bowed convexly considerably due to the pivoting action about fulcrum 254, but such extreme bowing may tend to be somewhat of an exaggeration in reality. In any event the flexed configuration per se of this lower part is not important as far as this invention is concerned. What is important is that there be some return bias present due to the rotation inwardly, and such is present because the end panel end portions making up the lower and upper part 272, 274 at each corner are made of material which has suflicient resiliency to spring back to their original rectilinear shape. In fact, all of the blank is preferably made of such material, any material such as paperboard well known in the art for making cartons and the like.

Because of such resiliency in the end panel end portions, upon release of the force causing the flaps to be rotated as in FIGURES 4 and 5, those end portions return to their upright position as required by the respective stops or abutments 248 at each corner. In so doing, the flap at each corner, as shown in FIGURE 6 interlocks securely with the slit thereat by the tab tip 260 staying on the inside of the side panel and extending above slit element 246 whereby the tab overlaps the slit with its inner edge 264 crossing the sloping slit element 244. With the flap in this locked position, it is positively locked therein by abutment 248 since no amount of inadvertent folding or the like of either end panel 212, 216 about its hinge with the main panel 208 can cause any unlocking of the secured corners. To effect an unlocking, a re-application of pressure to upper part 274 sufficient to rotate tip 260 below slit element 246 so it can slip back therethrough is required. Such force is not likely to be encountered in handling and use of a carton once it is initially set up.

Though it is preferable to have the tab and slit dimentioning such that there is substantially no play therebetween after the end panels return to rectilinear form and are in full abutment against lower end edge 248, but such is not an absolute requirement as long as the play is not so great as to allow any tab tip to become untucked thereby or by only slight pressure on upper portion 274. Additionally, as previously indicated, abutments 248 need not be at 90" to their respective fold lines 206 and 204, but may at any desired acute or oblique angle relative thereto, as long as the upper portion 25b is inwardly relieved from alignment with lower portion 248 by an angle preferably in the lower acute range such as the 12 above mentioned.

Intersection 254 forms a fulcrum as above indicated, and it also effects a stop of end panel rotation about its hinge as does abutment 248 as a whole. It is to be realized, however, that all is required is a stop and fulcrum, meaning that edge 248 could slope or meander inwardly from the stop-fulcrum point 254, if desired, though such is not preferable.

Even though FIGURE 1 and the discussion above have indicated the blank to be of the type in which opposite outside panels each have their two ends similar in configuration, it will be appreciated that the flap and slit arrangement at any corner of the blank may be reversed so that, for example end panel 212 would have a slit at one end for cooperation with a flap added to the end of side panel 210 but at its other end have the flap 220 as shown.

It will be appreciated from the foregoing that neither the tab 258 nor any other part of any end flap needs to be bent to get the tip 260 tucked into their respective slits, as the prior art requires. Because of the absence of this requirement and the presence of a simple force to execute the operation of pivoting the end panels about a fulcrum, the carton blanks of this invention may be set up not only manually but also automatically in accordance with the following discussion of inventive apparatus constructed in accordance with this invention.

Carton or like erecting machine capable of setting up into box form a cut and scored flat box blank are well known in the art. In general, such machines include a means for receiving a stack of flat box blanks, means for feeding successive individual flat box blanks between a plunger and die assembly which cooperate in response to relative vertical reciprocating movement to effect erection of the blank into box form, and means for receiving the erected boxes and conveying them from the machine. Since the present invention relates in its apparatus aspect only to improvements in the plunger and die assembly, the remaining elements of the machine have not been shown in the drawings. It Will be understood that the present plunger and die assembly is arranged to receive box blanks from any suitable box blank feeding means and to discharge the blanks in box form onto a suitable receiving and conveying means.

As shown by dash lines in FIGURE 7, the present plunger and die assembly is particularly adapted to set up fiat box blanks of the type shown in FIGURE 1.

The plunger and die assembly of the present invention is arranged to receive successive blanks therebetween and to set up such blanks into box form by relative vertical reciprocating movement between the plunger and die. In normal operation, the assembly is embodied in a machine provided with means for feeding successive blanks thereto. To this end, there is shown in FIGURE 7 a portion of the arrangement for guiding successive blanks horizontally into operative position between the plunger and die assembly. As shown, this guiding arrangement includes a pair of transversely spaced guide members 26 preferably in the form of angle irons. Preferably, each angle iron is disposed so that one of its flanges is horizontal and the other flange is vertical and extends upwardly from the first. In addition, the angle irons are positioned so as to converge slightly toward the plunger and die assembly so as to have a guiding effect on the blanks as they are moved therealong by means not shown. The horizontal surface of the blanks are preferably supported by a pair of transversely spaced supporting plates 28, each secured to the horizontal flange of an associated guide member 26'. V

The die of the present plunger and die assembly comprises a pair of elongated side wall members 30 and 32 preferably in the form of plates vertically elongated rectangular cross-sectional configuration. The side wall members are mounted in spaced parallel relation by any suitable means, such as lower cross braces 34 extending between opposite ends of the side wall members adjacent the lower surfaces thereof and upper cross braces 36 extending between the side wall members at positions spaced inwardly from the lower cross braces 34.

The central portion of the side wall member 30 defines a side wall engaging and folding means of the die. Secured to the central portion of the other side wall member 32 to define another side wall engaging and folding means of the die is a central plate 38 and two end plates 40. The plates 38 and 40 are secured to the side wall 32 by any suitable means in positions so that each end plate 40 is spaced from the associated end of the central plate 38 to define a channel or space 42 in one side face of the die.

It will be noted that the upper surfaces of the blank supporting plates 28 are disposed above the upper surface of the side wall member 30, as shown in FIGURE 2. In order to guide the blank into proper position over the die and beneath the plunger, each upper cross brace 36 has mounted thereon a guide member 44 in the form of an angle iron having one flange disposed horizontally in engagement with the upper surface of the associated cross brace 32 and secured therewith by any suitable means, such as bolts 46 extending through transversely elongated slots 48 formed in the horizontal flange of the guide member. Each guide member 44 also includes a vertical flange extending upwardly from the horizontal flange and arranged to engage an edge of the flat blank as it is moved horizontally into operative position over the die. Mounted on the outer end of the vertical flange of each guide member 44 in a position adjacent the side wall member. 32 is a stop block 50 which is arranged to engage the end flap of the blank outwardly of the associated tab '24. The guide members 44 thus serve to position each blank in proper relation to the die in one direction while the stop blocks 50 serve to properly position the blank in the other direction. A supporting plate 52 is secured to the upper surface of each cross brace 36 inwardly adjacent the associated vertical flange of the guide member 44 to support the associated end wall of the blank as it is moved horizontally into operative position.

In order to prevent the possibility of the blank buckling as a result of the leading edge of the leading side wall 12 of the blank engaging the plates 38 and 40 of the die during the movement of the blank into operative position, there is provided a pair of pivoted finger assemblies, generally indicated at 54. Each pivoted finger assembly includes a block 56 secured to the outer surface of the side wall 32, as by bolts 58. The upper surface of each block 56 is provided with a rectangular recess 60 which is aligned with the space 42 between the central plate 38 and associated end plate 40. In addition, an aligned recess 62 is formed in the upper surface of the side wall member 32.

Pivotally mounted within the recess 60, as by pivot pin 64, is a block 66 having a finger or guide member 68 mounted in its upper surface. Each finger 68 is provided with an upper surface having a rearward portion 70 which is normally disposed in a horizontal position and a forward portion 72 disposed at an angle of approximately 30 with respect to the rearward portion. The weight of each block 66 and finger 68 is distributed relative to the associated pivot pin 64 so as to bias or maintain the surface portion 70 in its horizontal position and the surface portion 72 in a position extending downwardly in front of the associated plates 38 and 40. If the leading edge of the leading side wall 12 of the blank during its horizontal movement into operative position over the die should curl under, it will be engaged by the inclined surface portions 72 and forced upwardly thereby over the upper surface of the plates 38 and 40 until the leading side wall 12 rests on the surface portions 70.

The inner surface of the side wall member 30 and the inner surfaces of the plates 38 and 40 define the sides of a cavity 74 of the die, the ends of which are formed by a pair of end wall members 76. Each end wall member 76 has one end thereof extending within a vertically elongated recess 78 formed in the side wall member 30 and connected therewith by a pivot pin 80 extending through the side wall member 30 and the upper portion of the end wall member 76. The end plate 40 associated with each end wall member 76 has its lower outer corner cut out, as indicated at 82 in FIGURE 8, to receive the opposite end of the associated end wall member 76, and the latter is connected with the side wall member 32, as by a pivot pin 84 extending therethrough and into the upper portion of the associated end wall member in alignment with the associated pivot pin 80.

The inner edges of the recess 78 and cut out 82 engage the lower forward edge of the associated end wall member 76 so as to limit the inward pivotal movement thereof. Each end wall member 76 is resiliently biased for inward movement by any suitable means, such as a pair of spaced coil springs 88 suitably connected between the lower end of the associated end wall member 76 and the associated lower cross brace 34.

Carried by the side wall member 30 adjacent each corner of the cavity 74 is an outer end portion blank engaging assembly 90 and .a similar assembly 92 is carried by the opposite side wall member 32 at each associated corner of the cavity 74. Each assembly 90 includes a spring pressed member in the form of a ball 94 mounted within a vertically extending aperture 96 extending through the side wall member 30. A bar 98 is secured to the outer surface of the side wall member 30 adjacent the aperture 96 and has an aligned aperture 100 formed therein. A coil spring 102 is mounted within the aperture 100 and has one end thereof disposed in engagement with a plate 104 secured to the bar 98 and its other end disposed in engagement with the ball to resiliently urge the latter toward the cavity. The inner end of the aperture 96 is reduced in cross-section to prevent the movement of the ball beyond a limiting position wherein the periphery extends into the die cavity 74.

Each assembly 92 includes a ball 106 mounted within an aperture 108, similar to aperture 96, extending through the associated end of plate 40. The side wall 32 has an aligned aperture 110 formed therein for receiving a coil spring 112 having one end engaging the ball 106 and its other end engaging a plate 114 suitably secured to the outer surface of the side wall member 32, as by bolts 116. The ball 106 is resiliently biased by the spring 112 into a limiting position in a manner similar to the ball 94.

The plunger of the present plunger and die assembly comprises a body, generally indicated at 118, which is preferably in the form of a casting. The body 118 includes a central, horizontally disposed portion 120 having end walls with upwardly extending successive outer surfaces 122 and 123 the latter being inwardly inclined at the same angle as the corresponding portion of the carton side panel end edge 250. Parallel side walls 124 and 126 extend downwardly from opposite sides thereof, the side wall 126 having a portion extending upwardly above the central horizontal portion 120. Formed in each side wall 124 and 126 is a pair of vertically extending slots or recesses 128, each slot being spaced from the associated end wall a distance slightly greater than the corresponding distance of the cut or slit from the associated end of the side flap. The purpose of each recess is to permit ready entry of the associated tab during the interlocking of the tab and slit.

The portion of each sidewall extending from each recess 128 to the associated end of the body is relieved as indicated at 130. The relief 130 (FIGURE 7) is preferably along a plane which extends in a horizontal direction inwardly from the adjacent plunger end at an angle of approximately 7 /2 and which extends vertically inwardly and upwardly an angle of approximately 7 /2. Preferably, a slight vertical marginal edge is provided, as indicated, at 132. Associated with'each slot 128 is a plate 134 rigidly secured, as by bolts 136, to each side wall adjacent to and inwardly of each slot. The upper outer end of each plate 134 has an inclined blank receiving knife edge 138 formed thereon and disposed at an angle of approximately 45 with respect to a horizontal outer edge 139. Each plate also includes a vertical outer edge 140 spaced inwardly from the adjacent outer slot wall to define a space for receiving the associated blank tab.

The end walls 122, 123 and sidewalls 124 and 126 of the die body 118 have their lower surfaces disposed in a common horizontal plane or forward end 142, for the purpose of engaging the bottom panel of the blank. It will be understood that the peripheral dimensions of the surface 142 are slightly less than the corresponding dimensions of the die cavity 74.

As noted above, the plunger and die assembly described above is arranged to be embodied in a machine having means for feeding successive flat box blanks thereto and means for receiving the set-up box blanks and conveying the same away from the machine. Preferably, the feeding means is arranged so as to move successive blanks horizontally into an operative position over the die cavity 74. To this end, the plates 28 serve to support the blanks for horizontal movement into such position while the vertical flanges of the guide members 26 serve to insure that the blank will move into proper operative position between the flanges of the die guide members 44. As noted above, the finger assemblies 54 are mounted so that they normally assume a position wherein the surface portions 70 are disposed horizontally and the surface portions 72 extend downwardly in front of the plates 38 and 40 at an angle of approximately 30. Thus, as the blank is moved horizontally over the die cavity the leading edge of the leading side panel 12 may engage the inclined surface portions 72 and be forced upwardly onto the horizontal surfaces 70. This action insures that the leading edge will not engage the plates 38 and 40 so that the blank will buckle during its movement into operative position. The horizontal movement of the blank is limited by engagement of stop blocks 50 therewith. In operative position, the blank is disposed as clearly indicated in dotted lines in FIGURE 1, with the main bottom panel 10 of the blank in transverse and longitudinal registry with the die cavity 74, and the end walls 20 of the blank resting on the plates 52.

It will be understood that when the present plunger and die assembly is embodied in an operative machine, means will be provided for effecting a relative vertical reciprocation between the plunger and die. Preferably, the side wall members 30 and 32 are rigidly secured to the frame of the machine while the plunger is suitably carried by a cross head mounted for vertical reciprocation on the frame of the machine. In this way, the plunger is mounted for vertical reciprocation through the cavity of the die.

Referring now more particularly to FIGURE 8, it will be noted that the plunger is disposed in a raised position above the die as the blank is moved into operative position over the die. The blank is set up during the subsequent vertical movement of the plunger through the die cavity. It will be noted that during the initial engagement of the surface 142 of the plunger body with the bottom panel of the blank, the finger assembies 54 will be pivoted in a counter-clockwise direction looking at the left end of FIGURE 8. At the same time side panels 210, 214 and end flaps 220, 224, 230, 232 of the blank begin their upward folding movement.

Subsequently, the end panels 212, 216 engage the upper end of the end wall members 76 of the die and begin their upward folding movement. As the plunger progresses downwardly into the die cavity 74, the spring pressed balls 94 and 166 engage the outer end portions 268 of the side panels of the blank, the latter being moved progressively downwardly past the balls so that the outer end portions are deflected inwardly against the relieved portions 130 of the plunger. The inner end portions 270 of the side panels of the blank are maintained in the plane of the side walls 124 and 126 of the plunger by engagement of the cut opening plates 134 therewith. This operation has the effect of opening the cuts or slits by relative deflection of the inner end portions 268 with respect to the outer end portions 270 adjacent the out.

Further downward movement of the plunger results in the further folding of the end panels into their upright positions against the lower outer abutment surfaces 122 of the plunger side walls. This further folding of the end panels is caused by the inward biasing effects on springs 88 on the pivoted side walls 76, the lower ends of which normally extend inside the die cavity 74 in the pathway of the respective outer surfaces 122 of the plunger, as indicated in FIGURE 8. The above mentioned further downward movement of the plunger also effects a comparable movement of the associated end flaps past the associated spring-pressed balls so that the tabs 258 move through the respective opened slits except for their tabs 26%. The outer edge 262 of each tab is guided past the associated plate 140 by the associated inclined knife edge 138 and is allowed to enter the plunger side recess 128 during its movement through the adjacent slit.

Still further downward movement of the plunger brings the lower inside corner of pivoted side wall members 76 adjacent the intersection of the plunger side wall surfaces 122 and 123, which intersection operates as a fulcrum, after which the side wall members 76 bend the respective end panels 212 and 216 about those plunger fulcrums, in a manner similar to that previously explained relative to FIGURES 4 and 5 and the fulcrums 254 formed in the end edge of the side panels. Such inward and downward rotation of the end panels about the respective plunger fulcrums, causes the tab tips to dip below the horizontal element 246 of the respective side panel slits, thereby putting each of the tabs 258 in position to cause their re spective interior edges 264 to lock positively with the sloping elements 244 of the slits upon further downward movement of the plunger whereby the side wall elements 76 come out of contact with the end panels and directly contact the plunger side walls themselves. This allows the carton end panels to spring back to their vertical position and effect the desired positive interlock.

Stripping of the erected and positively locked carton from the plunger may be accomplished in any conventional manner, as by suction cups or the like, or in the way indicated in the above mentioned Dunn patent. If desired, stripping can be left to the side wall members 76 during upward retraction of the plunger, since these side wall members are spring-biased against the plunger upper side walls without the carton end panels now being therebetween, and can therefore cause a relative downward movement of the carton as the plunger moves upwardly.

From a close comparison of the apparatus above described with that in the aforementioned Dunn patent, it will be appreciated that there are three significant changes in the apparatus as constructed in accordance with the present invention. First of all, and perhaps foremost, is the formation of the opposite side walls of the plunger into a fulcrum configuration by causing the side walls to have. outer surfaces 122 and 123 disposed at different angles, instead of these surfaces being a single surface sloping inwardly all at the same angle as in the Dunn patent. This is an important improvement in the apparatus, for it gives the fulcrum advantage so highly desirable as to cause proper flexing of the end panels of the carton as it is being set up.

Secondly, the apparatus differs from the aforementioned Dunn patent apparatus in that side wall members 76 on opposite sides of the die cavity are allowed to be biased further inwardly so that they will not only be in the pathway of the plunger surfaces 122, but also in the pathway of the upper plunger surfaces 123 sufiiciently to cause overbending' of the end panels in the desired manner.

The third change in the apparatus hereof, relative to that prior Dunn patent apparatus, relates to the slit or cut opening plates 134, specifically, the shortening of the sloping knife edge .138 and the addition of the horizontal edge 139, to conform with the desired configuration of the slits in each of the side panels 210 and 214.

With these three changes it is fully possible to erect the carton of this invention, automatically, as by machinery such as described herein, in contrast to the cited prior art type cartons which could not be so erected, or would not present a positive interlock if so erected.

Though this application has generally indicated that all sizes of the carton are set up, it will be appreciated that such is not necessary, for in certain instances it may be desired to leave one, or perhaps more, outside panels unerected, while the others are erected, in order to allow bakery goods or the like to be slid into the carton.

It will thus be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing specific embodiments of this invention have been shown and described only for the purpose of illustrating the principles of this invention and are subject to extensive change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

What is claimed is:

1. In a machine for setting up into erected operative position, at least part of a carton blank of the type including a main panel and a plurality of side panels hinged to the edges of said main panel for movement from a blanked position wherein said side panels are disposed in the plane of said main panel and an erected operative position wherein said side panels are disposed at an angle with respect to said main panel to form a container or cover, and in which at least one adjacent pair of end portions of adjacent side panels includes a flap defining a tab hinged to one of said pair of side panel end portions for movement from a blanked position wherein said flap is disposed in the plane of the associated side panel and a locking operative position wherein the interior surface of said flap is disposed in substantially abutting relation to the adjacent exterior surface of the other of said pair of side panel end portions and a cut for-med in said other side panel end portion for receiving said tab inwardly theretl irough when said flap is disposed in said locked operative position, said out and tab being so related that when the associated side panels are disposed in said erected operative position said tab overlaps said out in the locked operative position thereof so that said tab is prevented from movement out of said out without a deflection of at least a portion of the blank out of its operative position, with the end edge of said other side panel end portion including a stop portion shaped and positioned to engage the interior surface of said one side panel end portion adjacent the hinged flap thereon and prevent a non-deflecting movement of said one side panel end portion into a position wherein said tab is disposed out of overlapping relation with said cut, said end edge also in cluding a relieved portion extending angularly outwardly from said stop portion and of a size and shape suflicient to permit said one end portion and flap to be flexed about said stop portion as a fulcrum to thereby effect movement of said tab out of overlapping relation with said out and permit complete entry of said tab through said cut,

said machine being of the type which has a die forming a cavity and a plunger cooperatively movable relative to said die through the cavity thereof to at least partially set up a carton blank positioned therebetween, the improvement in said die and plunger of: side panel fulcrum forming means on said plunger, and means operatively connected to said die for flexing the outer part of at least the said end portion of said one side panel inwardly about said fulcrum means to cause the aforesaid entry of said tab through said cut.

2. The improvement as in claim 1 wherein the said side panel fulcrum forming means includes a side wall in said plunger having first and second outer surfaces respectively proceeding from the forward end of said plunger, said second surface being inwardly disposed relative to said first surface and forming therewith an intersection about which the said outer part of said one side panel end portion is flexed.

3. In a machine for setting up into erected operative position, at least part of a carton blank of the type including a main panel and a plurality of side panels hinged to the edges of said main panel for movement from a blanked position wherein said side panels are disposed in the plane of said main panel and an erected operative position wherein said side panels are disposed at an angle with respect to said main panel to form a container or cover, and in which at least one adjacent pair of end portions of adjacent side panels includes a flap defining a tab hinged to one of said pair of side panel end portions for movement from a blanked position wherein said flap is disposed in the plane of the associated side panel and a locking operative position wherein the interior surface of said flap is disposed in substantially abutting relation to the adjacent exterior surface of the other of said pair of side panel end portions and a cut formed in said other side panel end portion for receiving said tab inwardly therethrough when said flap is disposed in said locked operative position, said cut and tab being so related that when the associated side panels are disposed in said erected operative position said tab overlaps said cut in the locked operative position thereof so that said tab is prevented from movement out of said cut without a deflection of at least a portion of the blank out of its operative position, with the end edge of said other side panel end portion including a stop portion shaped and positioned to engage the interior surface of said one side panel end portion adjacent the hinged flap thereon and prevent a nondeflecting movement of said one side panel end portion into a position wherein said tab is disposed out of overlapping relation with said cut, said end edge also including a relieved portion extending angularly outwardly from said stop portion and of a size and shape sufilcient to permit said one end portion and flap to be flexed about said stop portion as a fulcrum to thereby eifect movement of said tab out of overlapping relation with said cut and permit complete entry of said tab through said cut,

said machine being of the type which has a die forming a cavity having two adjacent side walls one of which is inwardly biasingly pivotable at least at one end and which machine has a plunger cooperatively movable relative to said die through the cavity thereof to at least partially set up a carton blank positioned therebetween, the improvement comprising: said plunger having first and second adjacent side walls respectively corresponding to the said pivotable and the other said cavity side walls for cooperating therewith to respectively set up the said one and other adjacent side panels of said blank interlockingly, the said first side walls of said plunger including stop means at least at one end thereof which corresponds to the said one end of the pivotable cavity side walls for assisting said stop portion in initially engaging and stopping the hinge movement of said one id panel end portion relative to said main panel a caused by cooperation between said plunger first side wall and pivot-able cavity wall during movement of the plunger through said cavity, and

means, including means in said plunger first side wall cooperating with said pivotable cavity side wall, for causing the said one side panel end portion to have its outer portion flexed in the angular direction of said hinge movement about said stop means as a fulcrum by said pivotable wall to cause the aforesaid entry of said tab through said cut.

4. In a method for setting up into erected operative position at least part of a carton blank of the type including a main panel and a plurality of side panels hinged to the edges of said main panel for movement from a blanked position wherein said side panels are disposed in the plane of said main panel and an erected operative position wherein said side panels are disposed at an angle with respect to said main panel to form a container or cover, and in which at least one adjacent pair of end portions of adjacent side panels includes a flap defining a tab hinged to one of said pair of side panel end portions for movement from a blanked position wherein said flap i disposed in the plane of the associated side panel and a locking operative position wherein the interior surface of said flap is disposed in substantially abutting relation to the adjacent exterior surface of the other of said pair of side panel end portions and a cut formed in said other side panel end portion for receiving said tab inwardly therethrough when said flap is disposed in said locked operative position, said cut and tab being so related that when the associated side panels are disposed in said erected operative position said tab overlaps said cut in the locked operative position thereof so that said tab is prevented from movement out of said cut without a deflection of at least a portion of the blank out of its operative position, with the end edge of said other side panel end portion including a stop portion shaped and positioned to engage the interior surface of said one side panel end portion adjacent the hinged flap thereon and prevent a non-deflecting movement of said one side panel end portion into a position wherein said tab is disposed out of overlapping relation with said cut, said end edge also including a relieved portion extending angularly from said sto portion and of a size and shape sufiicient to permit said one end portion and flap to be flexed about said stop portion as a fulcrum to thereby effect movement of said tab out of overlapping relation with said cut and permit complete entry of said tab through said cut, the improvement of:

stopping the said one side panel end portion and its said flap during the movement of the said flap into said out before the tab completely enters said cut,

and then flexing the said one side panel end portion about the said stop portion toward said relieved portion to cause complete entry of said tab through said cut.

5. The method of claim 4 including applying pressure on the outer part of the outside surface of the said one side panel end portion at least adjacent the hinged flap thereon to cause the said flexing.

6. In a machine for setting up at least part of a sheet material blank of the type which is foldable to form a carton or the like having a plurality of corners, the area of the blank for one of said corners being formed by first and second outside panels and an inside panel to which said outside panels are hinged respectively along adjacent inside panel edges which intersect at an angle corresponding to the angle of said one corner, said first outside panel having an end edge which ends substantially at the said intersection of said inside panel edges, said second outside panel being resilient at least at its end part adjacent said intersection and having'hinged to the end edge of said part a flap which defines a locking tab having a tip, said end edge of said first panel forming in successive portions from said intersection respective first and second angularly displaced abutments for corresponding first and second portions of said resilient second panel end part, said first panel having an internal slit adjacent its said end edge for receiving said locking tab, when said second panel is folded about its hinge with the said inside panel to cause the said first portion of said resilient second panel end part to engage said first abutment, to the exclusion of said tab tip if at least the said second portion is not then substantially flexed toward said second abutrnnt but to the inclusion of said tip if said second portion is so fiexedand substantially engages said second abutment, I

said machine being of the type to set up at least the said one corner of said blank and which has a die forming a cavity and a plunger cooperatively movable relative to said die through the cavity thereof to at least partially set up a said blank positioned therehet'wecn, the improvement in said die and plunger of:

Wall means on said plunger and having first and second angularly displaced outer surfaces respectively corresponding in point of intersection and extent therefrom to the said first and second angularly displaced abutments on the end edge of the said first panel, and

means operatively connected to said die for flexing the outer part of at least the said second panel end part inwardly about the intersection of said first and second outer surfaces to cause the aforesaid inclusion of said tab tip in the receipt of said locking tab by said internal slit.

7. In a machine for setting up at least part of a sheet material blank of the type which is foldable to form a carton or the like having a plurality of corners, the area of the blank for one of said corners being formed by first and second outside panels and an inside panel to which said outside panels are hinged respectively along adjacent inside panel edges which intersect at an angle corresponding to the angle of said one corner, said first outside panel having an end edge which ends substantially at the said intersection of said inside panel edges, said second outside panel being resilient at least at its end part adjacent said intersection and having hinged to the end edge of said part a flap which defines a locking tab having a tip, said end edge of said first panel forming in-successive portions from said intersection respective first and second angularly displaced abutments for corresponding first and second portions of said resilient second panel end part, said first end edge abutment forming a substantially straight line proceeding from said intersection at an angle of approximately 90 relative to the hinge line of said first and inside panels, said second abutment forming a substantially straight line disposed at an acute angle relative to the said hinge line, the said intersection of said first and second abutments being on a line which is parallel spaced from said hinge line at approximately halfway between the outer edge of said first panel and the hinge line thereof with said inside panel, said first panel having an internal slit adjacent its said end edge for receiving said locking tab, when said second panel is folded about its hinge with the said inside panel to cause the said first portion of said resilient second panel end part to engage said first abutment, to the exclusion of said tab tip if at least the said second portion is not then substantially flexed toward second abut- 14 rn'ent but to the inclusion of said tip it said second portion is so flexed and substantially engages said second abutr'rient,

said machine being of the type which has a die forming cavity having two adjacent side walls one of which is inwardly biasingly pivotable and which machine has a plunger cooperatively movable relatiVe to said die through the cavity thereof to at least artially set up a carton blank positioned therebetween, the improvement comprising: said plunger having first aiid second adjacent side walls respectively corresponding to the said pivotable and the other cavity side walls for cooperating therewith to respectively set up the said second and first out side panels of said blank interlockingly, the said first side wall of said plunger including first and second outer surfaces successively disposed from the forward end of said plunger which cooperates with said inside panel at the same angle as said first and second abutments for said first panel end edge proceed from the first and inside panels hinge line, said first outer surface being of the same width as said first abutment, and means allowing movement of said pivotable cavity side wall into the space of said cavity considerably beyond the path followed by the intersection of the forward end of the plunger and the said first outer surface of its said first side wall for causing the pivotable cavity side wall to press the said second side panel first portion against said first outer surface and then the sec-ond portion of said second panel against the said second outer surface to bend the said second panel about the intersection of the said first and second outer surfaces of said plunger first side wall to cause the aforesaid entry of said tab through said out.

8. In a method for setting up at least part of a foldable blank of the type in claim 7, said method being of the type which includes:

folding said first and second outside panels relative to each other and relative to said inside panel at substantially right angles to cause formation of said one corner with said flap being folded at substantially a right angle to said second side panel and being on the outer side of said first panel except for the tab portion thereof which is through said slit and therefore on the inside of said first panel, said tab portion excluding said tip which is still on the said outer side of said first panel, and

bending said second side panel about the intersection of said first and second abutments to cause rotation of said flap toward the inside and first outside panel hinge line so that said tab tip proceeds completely through said slit to cause said tab to biasingly lock in said slit upon release of the force producing said bending.

References Cited UNITED STATES PATENTS 2,930,294 3/1960 Ritscher 93--51 3,028,797 4/1962 Bayley et al. 93-5 1 3,029,712 4/1962 Dunn 93-51 3,081,675 3/ 1963 Dion 93-51 FOREIGN PATENTS 556,567 8/ 1932 Germany.

BERNARD STICKNEY, Primary Examiner, 

1. IN A MACHINE FOR SETTING UP INTO ERECTED OPERATIVE POSITION, AT LEAST PART OF A CARTON BLANK OF THE TYPE INCLUDING A MAIN PANEL AND A PLURALITY OF SIDE PANELS HINGED TO THE EDGES OF SAID MAIN PANEL FOR MOVEMENT FROM A BLANKED POSITION WHEREIN SAID SIDE PANELS ARE DISPOSED IN THE PLANE OF SAID MAIN PANEL AND AN ERECTED OPERATIVE POSITION WHEREIN SAID SIDE PANELS ARE DISPOSED AT AN ANGLE WITH RESPECT TO SAID MAIN PANEL TO FORM A CONTAINER OR COVER, AND IN WHICH AT LEAST ONE ADJACENT PAIR OF END PORTIONS OF ADJACENT SIDE PANELS INCLUDES A FLAP DEFINING A TAB HINGED TO ONE OF SAID PAIR OF SAID PANEL END PORTIONS FOR MOVEMENT FROM A BLANKED POSITION WHEREIN SAID FLAP IS DISPOSED IN THE PLANE OF THE ASSOCIATED SIDE PANEL AND A LOCKING OPERATIVE POSITION WHEREIN THE INTERIOR SURFACE OF SAID FLAP IS DISPOSED IN SUBSTANTIALLY ABUTTING RELATION TO THE ADJACENT EXTERIOR SURFACE OF THE OTHER OF SAID PAIR OF SIDE PANEL END PORTIONS AND A CUT FORMED IN SAID OTHER SIDE PANEL END PORTION FOR RECEIVING SAID TAB INWARDLY THERETHROUGH WHEN SAID FLAP IS DISPOSED IN SAID LOCKED OPERATIVE POSITION, SAID CUT AND TAB BEING SO RELATED THAT WHEN THE ASSOCIATED SIDE PANELS ARE DISPOSED IN SAID ERECTED OPERATIVE POSITION SAID TAB OVERLAPS SAID CUT IN THE LOCKED OPERATIVE POSITION THEREOF SO THAT SAID TAB IS PREVENTED FROM MOVEMENT OUT OF SAID CUT WITHOUT A DEFLECTION OF AT LEAST A PORTION OF THE BLANK OUT OF ITS OPERATIVE POSITION, WITH THE END EDGE OF SAID OTHER SIDE PANEL END 